Controlling Onchocerciasis (River Blindness) in Sub-Saharan Africa

Case 7 Controlling Onchocerciasis (River Blindness) in Sub-Saharan Africa Geographic area: Sub-Saharan Africa Health condition: In west African countries in 974, nearly 2 million of the area’s 20 million inhabitants were infected with onchocerciasis, and approximately 200,000 were blind. Global importance of the health condition: Onchocerciasis, or river blindness, afflicts approximately 42 million people worldwide, with well over 99 percent of its victims in sub-Saharan Africa. An estimated 600,000 people are blind, and an additional .5 million Africans are visually impaired due to onchocerciasis. Intervention or program: The Onchocerciasis Control Program (OCP) was launched in 974 in west African countries. Weekly aerial spraying with environmentally safe insecticides helped control the disease vector—blackflies that bred in fast-moving waterways, thereby halting transmission of the disease. In 995, a second program, the African Programme for Onchocerciasis Control (APOC), was established to control the disease in 9 central, east, and southern African countries. Through a broad international partnership and the participation of 5,000 remote, rural communities, APOC and OCP distributed a drug donated by Merck & Co., Inc., Mectizan (ivermectin), to more than 45 million people in sub-Saharan Africa in 2005. The drug prevents and alleviates the symptoms of the disease with one annual dose. Cost-effectiveness: OCP operated with an annual cost of less than $ per protected person. Commit- ments from 27 donors during the 28-year project totaled $600 million. The annual return on investment was calculated to be about 20 percent, primarily attributable to increased agricultural output; about $3.7 billion will be generated from improved labor and agricultural productivity. The annual cost of APOC opera- tions, taking into account the donation of all needed drugs, is approximately $0.58 per person treated. Impact: OCP produced an impressive change in health between 974 and 2002: Transmission of the disease-causing parasite was halted in west African countries, 600,000 cases of blindness were prevented, and 22 million children born in the OCP area are now free from the risk of contracting river blindness. About 25 million hectares of arable land—enough to feed an additional 7 million people per annum—is now safe for resettlement. APOC is expanding this success to central, east, and southern Africa, where 54,000 cases of blindness are expected to be prevented each year. t the headquarters of the World Bank, the as in a prominent square in Ouagadougou, Burkina WHO, the Carter Center, the multinational Faso, visitors see a distinctive statue of a child lead- pharmaceutical firm Merck, and the Royal ing a blind man—a symbolic reminder to passersby ATropical Institute of the Netherlands, as well of the part each partner played in the control of one of Africa’s most devastating diseases. The Onchocer- The first draft of this case was prepared by Jane Seymour and Molly ciasis Control Program (OCP) has earned its place Kinder; significant contributions to the current version were made by Bruce Benton. as one of the signal achievements of international CONTROLLING ONCHOCERCIASIS (RIVER BLINDNESS) IN SUB-SAHARAN AFRICA public health, demonstrating the power of collabora- productivity and spend a large portion of their income tion across countries and agencies, the importance of on extra health costs.3 long-term funding from the donor community, and the benefits of public-private partnership to bring On a community level, the disease has hindered eco- pharmaceutical innovation into large-scale use in nomic growth. The threat of the disease has led people developing countries. to abandon more than 250,000 square kilometers of some of the best arable land in west Africa. In the words The Disease of Dr. Ebrahim Samba, OCP’s director from 1980 to 1994, “Onchocerciasis therefore is a disease of human Onchocerciasis, or “river blindness,” is a pernicious beings and also of the land. It directly retards develop- disease that afflicts approximately 42 million people ment and aggravates poverty.” worldwide, with well over 99 percent of its victims resid- ing in sub-Saharan Africa. Primarily a rural disease, on- Combating the Disease: The chocerciasis disproportionately burdens the inhabitants Onchocerciasis Control Program of some of the poorest and most remote areas in Africa. Small, isolated areas in Latin America and Yemen also Colonial and ex-colonial entomologists attempted for are affected. In the most endemic areas, more than one many years to control the disease in the hardest-hit third of the adult population is blind, and infection areas, but achieved mixed results. Lasting results proved often approaches 90 percent of the population.1 elusive because the blackflies cover long distances (exceeding 400 kilometers with the wind currents) and The disease is caused by a worm, Onchocerca volvulus, cross national boundaries, rendering uncoordinated which enters its human victim through the bite of an national control efforts ineffective. infected blackfly. In the arable riverine areas where the flies breed, residents are bitten as many as 10,000 times The small-scale control efforts of the 1950s and 1960s a day. Once inside a human, the tiny worm grows to provided the seeds for the first regional OCP, which two to three feet in length, each year producing millions were codified at an international conference in Tunisia of microscopic offspring called microfilaria. These tiny in 1968.4 The disease, concluded conference partici- worms are so abundant that a simple snip of the skin pants, would be controlled if it could be addressed on a can expose hundreds of writhing worms. sufficiently large scale. Scientists from WHO and other experts contributed to the preparation of a regional The constant movement of the microfilarie through the control plan. Several donors expressed mild interest, but infected person’s skin causes a wide range of debilitating none was able to commit alone what was expected to be symptoms, including disabling and torturous itching, a 20-year, $120 million program covering at least seven skin lesions, rashes, muscle pain, weakness, and, in countries. its most severe cases, blindness. The disease is spread when a new blackfly bites an infected person and then Serendipity intervened. In 1972, the then-president of bites another person, thus repeating the infection cycle. the World Bank, Robert McNamara, visited west Africa Today, an estimated 600,000 people are blind due to on- to observe the impact of a long drought that was under- chocerciasis, and nearly 1.5 million are severely visually way. While visiting the rural areas of Upper Volta (now impaired.2 Burkina Faso), he witnessed the devastation caused by onchocerciasis; he saw many children leading blind Beyond the disabling health burden, onchocerciasis adults, and communities in which nearly all the adults inflicts tremendous social and economic damage on were blind. McNamara decided to spearhead an interna- individuals and entire communities. Self-esteem and tional effort to control the disease, committing his own concentration suffer, and the disease reduces marriage institution to a catalytic financing role.1 prospects for both women and men. Infected individuals often earn less money as a result of decreased The OCP was launched in 1974 under the leadership of the WHO, the World Bank, the Food and Agriculture CONTROLLING ONCHOCERCIASIS (RIVER BLINDNESS) IN SUB-SAHARAN AFRICA Organization (FAO), and the United Nations Develop- 100,000 were blind. Today, transmission of the disease ment Program (UNDP). Financing and donor support has been virtually halted, and some 1.5 million people were mobilized through the World Bank from a wide who once were infected with the disease no longer range of donor countries, multilateral institutions, and experience any symptoms. An estimated 600,000 cases private foundations. of blindness have been prevented, and 22 million children born in the area since the program’s inception are The program, the first large-scale health program ever free from the risk of river blindness. supported by the World Bank, set out to eliminate the disease first in 7—and eventually in 11—west African The economic impact has also been impressive. An es- countries.a The primary intervention was vector control timated 25 million hectares of unusable arable land— of the disease-spreading blackflies, with the goal of enough to feed an additional 17 million people per ultimately halting disease transmission. Helicopters annum—has become available for agricultural produc- facilitated the weekly spraying of larvicides during rainy tion and resettlement.5 In Burkina Faso, for example, seasons on the riverine areas most heavily populated by 15 percent of the country’s land that had been deserted blackflies. The aerial treatment, as well as hand spraying because of the disease has been completely reclaimed, of breeding grounds, persisted even through civil and and its new residents now enjoy a thriving agricultural regional conflicts and coups. economy.6 Up-to-date information was a key element in pro- The program, which formally concluded in December gram implementation. Detailed mapping of the 12,000 2002, was extremely cost-effective and had a yearly miles of remote rivers and epidemiological mapping cost of less than $1 per person protected. Total com- of onchocerciasis prevalence facilitated these efforts. A mitments from 27 donors during the

Load more